void patch_col(SPMAT *A, int col, int old_row, int old_idx, int row_num,
int idx)
#endif
{
SPROW *r;
row_elt *e;
if ( old_row >= 0 )
{
r = &(A->row[old_row]);
old_idx = sprow_idx2(r,col,old_idx);
e = &(r->elt[old_idx]);
e->nxt_row = row_num;
e->nxt_idx = idx;
}
else
{
A->start_row[col] = row_num;
A->start_idx[col] = idx;
}
}
SPMAT *spCHsymb(SPMAT *A)
#endif
{
register int i;
int idx, k, m, minim, n, num_scan, diag_idx, tmp1;
SPROW *r_piv, *r_op;
row_elt *elt_piv, *elt_op, *old_elt;
if ( A == SMNULL )
error(E_NULL,"spCHsymb");
if ( A->m != A->n )
error(E_SQUARE,"spCHsymb");
/* set up access paths if not already done so */
if ( ! A->flag_col )
sp_col_access(A);
if ( ! A->flag_diag )
sp_diag_access(A);
/* printf("spCHsymb() -- checkpoint 1\n"); */
m = A->m; n = A->n;
for ( k = 0; k < m; k++ )
{
r_piv = &(A->row[k]);
if ( r_piv->len > scan_len )
set_scan(r_piv->len);
elt_piv = r_piv->elt;
diag_idx = sprow_idx2(r_piv,k,r_piv->diag);
if ( diag_idx < 0 )
error(E_POSDEF,"spCHsymb");
old_elt = &(elt_piv[diag_idx]);
for ( i = 0; i < r_piv->len; i++ )
{
if ( elt_piv[i].col > k )
break;
col_list[i] = elt_piv[i].col;
scan_row[i] = elt_piv[i].nxt_row;
scan_idx[i] = elt_piv[i].nxt_idx;
}
/* printf("spCHsymb() -- checkpoint 2\n"); */
num_scan = i; /* number of actual entries in scan_row etc. */
/* printf("num_scan = %d\n",num_scan); */
/* now set the k-th column of the Cholesky factors */
/* printf("k = %d\n",k); */
for ( ; ; ) /* forever do... */
{
/* printf("spCHsymb() -- checkpoint 3\n"); */
/* find next row where something (non-trivial) happens
i.e. find min(scan_row) */
minim = n;
for ( i = 0; i < num_scan; i++ )
{
tmp1 = scan_row[i];
/* printf("%d ",tmp1); */
minim = ( tmp1 >= 0 && tmp1 < minim ) ? tmp1 : minim;
}
if ( minim >= n )
break; /* nothing more to do for this column */
r_op = &(A->row[minim]);
elt_op = r_op->elt;
/* set next entry in column k of Cholesky factors */
idx = sprow_idx2(r_op,k,scan_idx[num_scan-1]);
if ( idx < 0 )
{ /* fill-in */
sp_set_val(A,minim,k,0.0);
/* in case a realloc() has occurred... */
elt_op = r_op->elt;
/* now set up column access path again */
idx = sprow_idx2(r_op,k,-(idx+2));
tmp1 = old_elt->nxt_row;
old_elt->nxt_row = minim;
r_op->elt[idx].nxt_row = tmp1;
tmp1 = old_elt->nxt_idx;
old_elt->nxt_idx = idx;
r_op->elt[idx].nxt_idx = tmp1;
}
/* printf("spCHsymb() -- checkpoint 4\n"); */
/* remember current element in column k for column chain */
idx = sprow_idx2(r_op,k,idx);
old_elt = &(r_op->elt[idx]);
/* update scan_row */
/* printf("spCHsymb() -- checkpoint 5\n"); */
/* printf("minim = %d\n",minim); */
for ( i = 0; i < num_scan; i++ )
{
if ( scan_row[i] != minim )
continue;
idx = sprow_idx2(r_op,col_list[i],scan_idx[i]);
if ( idx < 0 )
{ scan_row[i] = -1; continue; }
scan_row[i] = elt_op[idx].nxt_row;
scan_idx[i] = elt_op[idx].nxt_idx;
/* printf("scan_row[%d] = %d\n",i,scan_row[i]); */
/* printf("scan_idx[%d] = %d\n",i,scan_idx[i]); */
}
}
/* printf("spCHsymb() -- checkpoint 6\n"); */
}
return A;
}
